Abstract: Understanding the pollution status and phytoplankton community structure characteristics of discharge tail water in container recirculating aquaculture system is helpful to improve the efficiency of water quality management and increase aquaculture benefits. In this study, water quality monitoring and phytoplankton sampling were carried out at outlet site A and inlet site B of the system. The difference analysis was used to compare the water quality and phytoplankton community structure between the site A and B. Redundancy analysis (RDA ) was used to analyze the correlation between phytoplankton and environmental factors and identify the main environmental factors affecting phytoplankton community structure. The results showed that the main pollutants were suspended solids (SS) and total nitrogen (TN), the pollutant concentration at site A higher than at site B, and the total pollution index was the highest in May. The removal rate of Ammonia nitrogen (NH4+-N) and SS in the purification area was higher than another pollutant. In addition, 98 species of phytoplankton were detected in the system, including 76 species at site A and 81species at site B, the average phytoplankton density, biomass, Shannon-Wiener diversity index and Margalef richness index were 12.25×106cell/L and 11.67×106cell/L, 26.69mg/L and 34.23mg/L, 1.87 and 1.93, 0.63 and 0.64 in the site A and B, respectively. SS was an environmental factor that significantly affected the phytoplankton community structure at site A, and NH4+-N, TN, total phosphorus (TP) and SS were environmental factors that significantly affected the phytoplankton community structure at site B. This research demonstrates that physical filtration and ecological purification can effectively reduce pollutant concentration and improve phytoplankton biodiversity in container recirculating aquaculture tail water.

Key words:  container recirculating aquaculture, ex-situ treatment, ecological pond, phytoplankton community structure

摘要： 为了解集装箱循环水养殖系统中排放尾水的污染状况及浮游植物群落结构特征，有效管理水环境质量，提高养殖效益。在系统集装箱养殖区的出水口（A）和进水口（B）进行水质监测和浮游植物采样分析，运用差异性分析比较两点的水质状况和浮游植物群落结构差异，运用冗余分析（RDA）浮游植物与环境因子的相关性并识别影响浮游植物群落结构的主要水环境因素。结果显示：系统主要污染物为悬浮颗粒物（SS）和总氮（TN），A点污染物质量浓度高于B点，5月的总污染指数最高，系统净化区域对尾水中的氨氮（NH4+-N） 和SS的去除率高于其他污染物。系统中检出浮游植物7门58属98种，A点76种，B点81种，均以绿藻门种类为主，A、B两点浮游植物密度、生物量、Shannon-wiener多样性指数和Margalef丰富度指数平均值分别为12.25×106 cell/L和11.67×106 cell/L，26.69 mg/L和34.23 mg/L，1.87和1.93，0.63和0.64。SS是显著影响A点浮游植物群落结构的环境因子，NH4+-N、TN、总磷（TP）和SS是显著影响B点浮游植物群落结构的环境因子。研究表明：运用物理过滤和生态净化等方法能有效降低集装箱养殖尾水中污染物质量浓度和提高浮游植物生物多样性。

关键词: 集装箱循环水养殖, 异位处理, 生态池塘, 浮游植物群落结构